MeasureThat.net

Run results for: is variable undefined? typeof variable === "undefined" vs variable === undefined

Comparing whether checking is (typeof variable === "undefined") is faster than (variable === undefined)

Go to the benchmark
Run details:
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36
Chrome 125
Linux
Desktop
4 months ago
Test name Executions per second
typeof string is undefined 68935088.0 Ops/sec
typeof undefined is undefined 4731379.0 Ops/sec
string is undefined 4600870.0 Ops/sec
undefined is undefined 2432677.2 Ops/sec
Tests:

  • typeof string is undefined

    AخA
     
    typeof "not undefined" === "undefined"

  • typeof undefined is undefined

     
    typeof undefined === "undefined"

  • string is undefined

     
    "not undefined" === undefined

  • undefined is undefined

     
    undefined === undefined